Over the years there has been a constant evolution of cleansing compositions for the human skin. From the basic use of lye soap to the more advanced combars and synthetic detergents compositions in both liquid and solid form, there has been a constant quest for improved compositions having better cleansing activity but with increased mildness to the skin as well as inter alia, better sensory attributes.
Although sulfates and carboxylates are still commonly used as surfactants, in the last few years attention has been drawn to phosphates utilized for that function. U.S. Pat. No. 4,139,485 issued Feb. 13, 1979 to Kao Corporation is directed to a composition utilized for skin care employing a mixture of two different phosphates, a monoalkyl phosphate and dialkylphosphate, the proportion of the dialkyl phosphate, if present at all, to be no more than 20 weight percent of the total mono and dialkylphosphate. Above 20 weight percent, the composition is stated to have substantially inferior foaming properties, water solubility and is unsuitable for use in detergent compositions of that invention, see column 7, lines 46-55 of U.S. Pat. No. 4,139,485. Recently U.S. Pat. No. 5,139,781 issued Aug. 18, 1992 to Cheseborough Ponds disclosed that the special proportions of monoalkylphosphate to dialkylphosphate necessary for proper foaming, water solubility and mildness of the previously mentioned Kao U.S. Pat. No. 4,139,485 were not necessary as long as there was at least one of a very limited family of co-surfactants also present in the composition. These cosurfactants were limited to either an alkylamidopropyl betaine or an alkylamphoglycinate. A host of additional supplementary surfactants could also be present but the two previously mentioned betaines or glycinates were critical to improving the foaming of the compositions as measured by foam height, perceived volume and creaminess. The additional supplementary surfactants were exhaustively described at column 5, line 25 through column 9, line 52 of the 781 patent.
It has now been discovered that a new cosurfactant group can be combined with mono and dialkylphosphate, ethoxylated or not, with levels of dialkylphosphate significantly above 20 wt %, as measured by total wt % mono and dialkyl phosphate and obtain a detergent composition which is mild, water soluble and produces a foam which enhances cleaning, and has specific advantages in flash foaming and total foam height.